Layer-by-layer assembly of homopolypeptide polyelectrolytes on asymmetric nanochannels for the detection of nickel ions

Nickel stands out as one of the prevalent heavy metal ionic pollutants found in water. It is urgent to devise a simple, efficient, budget-friendly, highly-selective and proficient method for detecting Ni(II). This work reports an approach to design a nanofluidic diode for the ultrasensitive and label-free detection of nickel ions based on layer-by-layer assembly of polyarginine (PA) and polyglutamic acid (γ-PGA) on the inner surface of asymmetric nanochannels. We can tune the adsorption/desorption characteristics of the asymmetric nanochannels for Ni2+ by adjusting the pH changes, i.e., the PA-γ-PGA modified nanochannels adsorb Ni2+ at pH 6 and desorb at pH 3 in aqueous solution. This pivotal adjustment facilitates the reusable and specific detection of nickel ions with a detection limit of 1 × 10-8 M. Moreover, the system demonstrates commendable stability and recyclability, enhancing its practical applicability. This innovative system holds promise for recognizing and detecting nickel ions in diverse environments such as water, blood, and cells. The robust performance and adaptability of our proposed system instill confidence in its potential for future applications.

Regioselective Dearomative Amidoximation of Nonactivated Arenes Enabled by Photohomolytic Cleavage of N-nitrosamides

Dearomative spirocyclization reactions represent a promising means to convert arenes into three-dimensional architectures; however, controlling the regioselectivity of radical dearomatization with nonactivated arenes to afford the spirocyclizative 1,2-difunctionalization other than its kinetically preferred 1,4-difunctionalization is exceptionally challenging. Here we disclose a novel strategy for dearomative 1,2- or 1,4-amidoximation of (hetero)arenes enabled by direct visible-light-induced homolysis of N-NO bonds of nitrosamides, giving rise to various highly regioselective amidoximated spirocycles that previously have been inaccessible or required elaborate synthetic efforts. The mechanism and origins of the observed regioselectivities were investigated by control experiments and density functional theory calculations.

Ultrasensitive and Label-Free Detection of Copper Ions by GHK-Modified Asymmetric Nanochannels

Artificial solid-state nanochannels have garnered considerable attention as promising nanofluidic tools for ion/molecular detection, DNA sequencing, and biomimicry. Recently, nanofluidic devices have emerged as cost-effective detection tools for heavy metal ions by modifying stimuli-responsive materials. In this work, high-purity glycyl-l-histidyl-l-lysine (GHK) peptide is synthesized by using 7-diphenylphosphonooxycoumarin-4-methanol (DPCM) as a protecting group and auxiliary carrier by homogeneous synthesis of photocleavable groups. Subsequently, we developed a GHK-modified asymmetric nanochannel nanofluidic diode by covalently attaching the GHK peptide to the inner surface of the nanochannels. This modification facilitated specific recognition and ultra-trace level detection of Cu2+ ions, achieving a detection limit of 10-15 M. Due to the robust complexing ability between Cu2+ and GHK peptide, the GHK-modified asymmetric nanochannels can form GHK-Cu complexes on the inner surface of nanochannels when Cu2+ passes through the nanochannels. This results in changes of current-potential (I-V) properties, which facilitated Cu2+ detection. Theoretical calculations confirmed the high affinity of the GHK peptide for Cu2+, thereby ensuring excellent Cu2+ selectivity. To evaluate the applicability of our system for detecting Cu2+ in real-world scenarios, we analyzed the concentration of Cu2+ in tap water. The GHK-Cu complexes could be dissociated by adding EDTA to the solution, enabling the regeneration and reuse of this ultrasensitive and label-free Cu2+ detection system using GHK-modified asymmetric multi-nanochannels. We anticipate that the GHK-modified asymmetric nanochannels will find future applications in the label-free detection of Cu2+ in domestic water.

[GNB2L1 gene expression and clinical value in hepatocellular carcinoma based on bioinformatics]

Objective: To analyze guanine nucleotide-binding protein subunit beta-2-like 1 (GNB2L1) expression based on bioinformatics, so as to evaluate its role and its relationship with survival rate during the occurrence and development of hepatocellular carcinoma. Methods: GEPIA, UALCAN and HPA databases were used to analyze the expression level of GNB2L1 and its relationship with HCC survival rate. Mutations in the GNB2L1 gene and their impact on survival were analyzed using the cBioPortal database. LinkedOmics database was used to analyze GNB2L1-related genes in HCC. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed simultaneously. STEING database was used to construct the GNB2L1 protein interaction network. TIMER database was used to analyze the relationship between GNB2L1 gene expression and immune infiltration in hepatocellular carcinoma. Differential expression of GNB2L1 in plasma platelets of HCC patients and healthy controls was analyzed using mRNA-based sequencing technology. Data between groups were compared using an independent-samples t-test. Results: GNB2L1 expression level was significantly increased in HCC tissues (P<0.05), and its expression was significantly correlated with body weight, classification and stage (P<0.05). The overall survival rate was higher in GNB2L1 low expression group (P<0.001). GNB2L1 and its related genes were related to biological process regulation, metabolic process, protein binding, oxidative phosphorylation, JAK-STAT signaling pathway, Ras signaling pathway and so on. GNB2L1 had interaction with RPS12, RPS11 and RPL19, and participated in multiple biological processes such as liver regeneration and positive regulation of endogenous apoptotic signaling pathway. GNB2L1 expression was significantly positively correlated with the infiltration degree of various immune cells in HCC (P<0.05). Cox regression analysis showed that GNB2L1 was an independent risk factor for lower survival rate in patients with HCC [Hazard ratio (95% confidence interval)=1.456 (1.034~2.051), P=0.031]. GNB2L1expression levels were significantly higher in platelets of HCC patients than that of healthy controls (10.40±1.36 vs. 9.58±0.51, t=2.194, P=0.037). Conclusion: GNB2L1 has high expression and close relationship to survival rate in HCC. Therefore, GNB2L1 may be a potential biomarker of HCC.

Flavanthrene derivatives as photostable and efficient singlet exciton fission materials

Singlet exciton fission (SF) is believed to have the potential to break the Shockley−Quiesser third-generation solar cell devices, so that attracted great attention. Conventional linear acene based SF materials generally...

Tunable nonlinear optical responses and carrier dynamics of two-dimensional antimonene nanosheets

Sb nanosheets, also known as antimonene, have received ever-growing consideration as a promising new type of two-dimensional (2D) material due to their many attractive properties. However, how their nonlinear optical (NLO) properties are affected by their nanosheet structure and measurement conditions remains unclear. Herein, we report a successful size-selective production method for Sb nanosheets, which is based on a combination of lithium ion intercalation, solvent exfoliation and size selection centrifugation. This high-yield and size-selective preparation method enables fundamental investigation on the relation of the intrinsic optical properties of Sb nanosheets. Nanosecond Z-scan measurements revealed a unique size-dependent broadband NLO response. When the average size is reduced from 3 micrometers to 50 nanometers, the Sb nanosheets exhibit a clear transition from saturable absorption to reversed saturable absorption. Ultrafast transient absorption spectroscopic investigation indicated that exciton cooling is significantly faster in a small nanosheet than in large ones, revealing that the different exciton relaxation dynamic plays key roles in the distinct size-tunable nonlinear optical response. This work paves new ways towards the mass production and practical application of antimonene.

Lasing from an Organic Micro-Helix

Organic solid-state semiconductor lasers are attracting ever-increasing interest for their potential application in future photonic circuits. Despite the great progress made in recent years, an organic laser from 3D chiral structures has not been achieved. Now, the first example of an organic nano-laser from the micro-helix structure of an achiral molecule is presented. Highly regular micro-helixes with left/right-handed helicity from a distyrylbenzene derivative (HM-DSB) were fabricated and characterized under microscope spectrometers. These chiral micro-helixes exhibit unique photonic properties, including helicity-dependent circularly polarized luminescence (CPL), periodic optical waveguiding, and length-dependent amplified spontaneous emission (ASE) behavior. The successful observation of laser behavior from the organic micro-helix extends our understanding to morphology chirality of organic photonic materials and provides a new design strategy towards chiral photonic circuits.

Bioinspired Dual-Responsive Nanofluidic Diodes by Poly-l-lysine Modification

A smart nanofluidic device attracts attention as it enables to control the physicochemical properties and transportation phenomena, by using stimuli-responsive materials. This work reports a bioinspired modification of a conical ion track-etched polyethylene terephthalate nanopore surface by coating a layer of poly-l-lysine (PLL), which is a commonly used coating in biotechnology to achieve a dual-responsive nanofluidic channel by pH or temperature. The rectification of ionic transportation can be reversed by assembling PLL because of the change of surface bonds from the carboxyl to amine group. The PLL-modified nanopore becomes nonconductive as an "OFF" state at pH 11.5 and at a temperature of 70 °C in solution. The ionic transport in nanopores can be switched to the "ON" (conductive) state, by either decreasing pH or temperature. The transitions between "ON" and "OFF" states present excellent reversibility, which make the PLL-modified nanopores a promising smart nanofluidic device that can be used for drug delivery or biomimic ion/mass transport in future, besides the good biocompatibility and ease of use of PLL modification.

Aromaticity and tautomerism of a 4n π electron dihydrohexaazapentacene

We report herein the intriguing tautomerism behaviors of new dihydrohexaazapentacene derivatives. The dihydrohexaazapentacene molecules with 4n π electrons exist as two stable tautomers in solution and exhibits globe aromaticity.

[A clinical analysis of 27 cases of simultaneous bilateral sudden sensorineural hearing loss]

Objective:To compare the clinical characteristics and therapeutic effects between simultaneous bilateral sudden sensorineural hearing loss（Si-BSSHL） and unilateral sudden sensorineural hearing loss（USSHL）. Method:The clinical data of 27 cases of Si-BSSHL were retrospectively analyzed, including the characteristics of the disease, clinical manifestations, audiological examination, hematological examination, and therapeutic effect, and compared with those of 139 cases of USSHL. Result:There was a statistically significant difference in the age（65.85±9.17 vs 56.95±13.18, P<0.01） and no significant difference in sex ratio（P>0.05） between the two groups. The proportion of Si-BSSHL patients with vertigo, ear fullness, hypertension, diabetes, coronary heart disease and stroke had no statistical difference compared with those of USSHL（P>0.05）, the proportion of patients with tinnitus in Si-BSSHL group was significantly lower than that in USSHL group（P<0.05）. The distribution of hearing loss degree and the type of audiometry in Si-BSSHL group were significantly different from those in USSHL group, PTA before treatment and the proportion of profound hearing loss in Si-BSSHL group was significantly lower than that in USSHL group（P<0.05）, descending audiometry type was more common in Si-BSSHL group compared to USSHL（P<0.01）. Fibrinogen in Si-BSSHL group was significantly higher than that in USSHL group（P<0.05）. No significant difference was found between the two groups with respect to mean platelet volume, blood lipid and folic acid（P>0.05）. The total treatment effective rate in Si-BSSHL group was 44.44%, while that in USSHL group was 41.73%, there was no significant difference between the two groups（P>0.05）. Conclusion:Si-BSSHL has a female preponderance and tends to occur in advanced age in our cohort. Compared to USSHL patients, Si-BSSHL patients have less profound hearing loss and more descending audiograms, and the proportion of patients with extremely severe deafness is relatively small. There is no significant difference in the therapeutic effect between the two groups.

Disentangling the Luminescent Mechanism of Cs4PbBr6 Single Crystals from an Ultrafast Dynamics Perspective

New all-inorganic perovskites like Cs₄PbBr₆ provide rich luminescent tools and particularly novel physical insights, including their zero-dimensional structure and controversial emitting mechanism. The ensuing debate over the origin of the luminescence of Cs₄PbBr₆ inspired us to tackle the issue through fabricating high-quality Cs₄PbBr₆ single crystals and employing ultrafast dynamics study. Upon photoexcitation, Cs₄PbBr₆ underwent dynamics steps distinct from that of CsPbBr₃, including exciton migration to the defect level on a time scale of several hundred femtoseconds, exciton relaxation within the defect states on the picosecond time scale, and exciton recombination from the subnanosecond to nanosecond time scale. The observation disclosed that crystal defects of Cs₄PbBr₆ induced green emission while CsPbBr₃ mainly relied on quantum confinement to emit at room temperature. The study provides an in-depth understanding of the photoinduced multistep dynamics steps of Cs₄PbBr₆ associated with display and photovoltaic applications, establishing Cs₄PbBr₆ as a new candidate for uses associated with the perovskite family of materials.

Construction of Dopamine-Releasing Gold Surfaces Mimicking Presynaptic Membrane by On-Chip Electrochemistry

We report a strategy to construct a dopamine-releasing gold surface mimicking a presynaptic membrane on a microfluidic chip to simulate in vivo neural signaling. We constructed dopamine self-assembled monolayers (DA SAMs) by electrochemical deprotection of methyl group-protected DA SAMs on a gold surface. Electrochemically controllable release of DA SAMs can be realized by applying nonhydrolytic negative potential on the gold surface. Our method in constructing DA SAMs avoids the polymerization and protonation of DA molecules which may lead to the failure of the DA SAM formation. By combining microfluidics, we realized spatial and temporal controllable release of DA by electrochemistry from the gold surface. Furthermore, by culturing neurons on the patterned DA SAMs, the interface between the DA SAMs and the neurons could serve as a presynaptic membrane, and the spatiotemporal release of DA could modulate the neuron activity with high precision. Our study holds great promise in the fields of neurobiology research and drug screening.

2D bismuthene fabricated via acid-intercalated exfoliation showing strong nonlinear near-infrared responses for mode-locking lasers

The rediscovery of black phosphorus (BP) has expanded the 2D family into Group 15 (Nitrogen Group) elements, among which bismuthene is the latest member with extraordinary opto-electronic, catalytic and biocompatible properties and potential as a 2D topological insulator. However, bulk Bi is not easily mechanically exfoliated as its counterpart of BP. Thus, to date, the reports on 2D Bi fabrication are rare, and investigations on its nonlinear optical properties are even less. Herein, we rationally designed a new strategy combining acid-interaction and liquid exfoliation to successfully transform metal bulk Bi into few-layer semiconductor, which resulted in unseen opto-electronic properties, such as tunable nonlinear responses all the way to the near-infrared (NIR) region. This band is critical for telecommunication and military purposes, but currently, functioning materials are extremely scarce. The origin of this strong saturable absorption was thoroughly explored through time-resolved spectroscopy spanning from the fs to μs timescale, which indicated ultrafast fs to ps carrier dynamics in the early stage and long exciton bleaching recovery up to μs. As a proof-of-concept application, the as-prepared 2D Bi was employed as a saturable absorber to mode-lock a Tm-doped fiber laser and successfully realized a 2 μm NIR-wavelength output. This study not only offers an effective and scalable method to fabricate the new 2D family member bismuthene with extraordinary stability, but also explores its strong and broad nonlinear responses extending into the NIR region and fundamental photoinduced dynamics, which demonstrate the full potential of 2D Bi for application in opto-electronic devices and nonlinear optics.

[The role of ¹⁸F-FDG PET/CT for detecting nodal metastases in cN0 head neck cancer patients：a Meta-analysis]

Objective:The aim of this study is to evaluate the accuracy of ¹⁸F-fluorodeoxyglucose PET/CT(¹⁸F-FDG PET/CT) for the diagnosis of cervical node metastases in cN0 head neck cancer patients. Method:An electronic database search（PubMed，EMBASE，Cochrane Library，WanFang and CNKI databases）was performed. Updated quality assessment of diagnostic accuracy studies-2(QUADAS-2) was used to assess study quality. Data analyses were performed with Meta-Disc1.4. Result:Eight studies were included in the present Meta-analysis. For patient-specific data，the pooled sensitivity，specificity，diagnostic odds ratio（DOR），positive likelihood ratio（PLR），and negative likelihood（NLR）for ¹⁸F-FDG PET/CT were 0.61（95%CI0.52-0.69）,0.74（95%CI0.68-0.78），9.62（95%CI2.49-37.22），3.22（95%CI1.55-6.71）,and 0.42（95%CI0.24-0.37）,respectively. The area under the curve（AUC）was 0.804 1.The evaluation of heterogeneity，calculated the pooled diagnostic odds ratio，gave aQvalue of 21.26（P<0.05）and an I²of 81.2%. Conclusion:The results of meta-analysis suggested that ¹⁸F-FDG PET/CT did not provide better diagnostic accuracy than CT/MRI in detecting cervical node metastases in cN0 head and neck cancer. Considering the high heterogeneity of the included studies，potential value of PET/CT needs to be validated in future studies.

Medium-Bandgap Small-Molecule Donors Compatible with Both Fullerene and Nonfullerene Acceptors

Much effort has been devoted to the development of new donor materials for small-molecule organic solar cells due to their inherent advantages of well-defined molecular weight, easy purification, and good reproducibility in photovoltaic performance. Herein, we report two small-molecule donors that are compatible with both fullerene and nonfullerene acceptors. Both molecules consist of an (E)-1,2-di(thiophen-2-yl)ethane-substituted (TVT-substituted) benzo[1,2-b:4,5-b']dithiophene (BDT) as the central unit, and two rhodanine units as the terminal electron-withdrawing groups. The central units are modified with either alkyl side chains (DRBDT-TVT) or alkylthio side chains (DRBDT-STVT). Both molecules exhibit a medium bandgap with complementary absorption and proper energy level offset with typical acceptors like PC₇₁BM and IDIC. The optimized devices show a decent power conversion efficiency (PCE) of 6.87% for small-molecule organic solar cells and 6.63% for nonfullerene all small-molecule organic solar cells. Our results reveal that rationally designed medium-bandgap small-molecule donors can be applied in high-performance small-molecule organic solar cells with different types of acceptors.

Solvent-Free Mechanosynthesis of Composition-Tunable Cesium Lead Halide Perovskite Quantum Dots

A facile and green mechanosynthesis strategy free of solvent and high reaction temperature was developed to fabricate highly emissive cesium lead halide perovskite (CsPbX₃) quantum dots (QDs). Their composition can be adjusted conveniently simply through mechanically milling/grinding stoichiometric combinations of raw reagents, thereby introducing a broad luminescence tunability of the product with adjustable wavelength, line width, and photoluminescence quantum yield. Desired CsPbX₃ QDs "library" can thus be readily constructed in a way like assembling Lego building blocks. Hence, the method offered new avenues in the preparation of multicomponent cocrystals, adding one appealing apparatus to the tool box of perovskite-type QDs synthesis. Intriguingly, photoinduced dynamic study revealed the hole-transfer process of the as-prepared QDs toward electron donors, indicative of their potential in charge-transfer-based applications such as light-harvesting devices and photocatalysis.

Ultrabright organic fluorescent microparticles for in vivo tracing applications

We report the in vivo distribution, toxicity and metabolism of micro-sized fluorescent organic particles and their applications in cerebral blood flow tracing. The fluorescent microparticles exhibit bright fluorescence, good photo-stability and low toxicity; therefore, they are ideal for long-term non-invasive in vivo tracing. In contrast to conventional fluorescent labeling agents, which stain the entire blood vessel, the tracer microparticles can be easily tracked individually and provide vital information about blood flow behavior. Furthermore, we observed stimulated emission from these microparticles in living animals. These microparticles can provide unprecedented contrast for simultaneous observation of the distribution of blood vessels and the dynamics of microcirculation. Pathological examination revealed that the injected microparticles eventually collected in the spleen and liver. We found no observable toxicity of the microparticles to cells or mouse organs. We demonstrate that these fluorescent microparticles are suitable for applications in the field of non-intrusive blood flow tracing and could play a complementary role to traditional imaging agents.

Rational design of small indolic squaraine dyes with large two-photon absorption cross section

Small organic dyes with large two-photon absorption (TPA) cross sections (δ) are more desirable in many applications compared with large molecules. Herein, we proposed a facile theoretical method for the fast screening of small organic molecules as potential TPA dyes. This method is based on a theoretical analysis to the natural transition orbitals (NTOs) directly associated with the TPA transition. Experimental results on the small indolic squaraine dyes (ISD) confirmed that their TPA cross sections is strongly correlated to the delocalization degree of the NTOs of the S₂ excited states. Aided by this simple and intuitive method, we have successfully designed and synthesized a small indolic squaraine dye (ISD) with a remarkable δ value above 8000 GM at 780 nm. The ISD dye also exhibits a high singlet oxygen generation quantum yield about 0.90. The rationally designed TPA dye was successfully applied in both two-photon excited fluorescence cell imaging and in vivo cerebrovascular blood fluid tracing.

Squaraines as light-capturing materials in photovoltaic cells

We have summarized the recent developments in the molecular design strategies of squaraines for photovoltaic applications.

Reproductive biology of female bigeye tuna Thunnus obesus in the western Pacific Ocean

The reproductive biology of female bigeye tuna Thunnus obesus was assessed by examining 888 fish (ranging from 84·9 to 174·4 cm fork length, LF ) caught by Taiwanese offshore longliners in the western Pacific Ocean from November 1997 to November 1998 and November to December 1999 and 258 gonad samples from these fish. The overall sex ratio of the catch during the sampling differed significantly from 0·5, but males were predominant in sizes >140 cm LF . Reproductive activity (assessed by histology), a gonado-somatic index, and the size-frequency distributions of whole oocytes indicated that spawning occurred throughout the year and the major spawning season appeared to be from February to September. The estimated sizes at 50% maturity (LF50 ) of females was 102·85 cm (95% c.i.: 90·79-110·21 cm) and the smallest mature female was 99·7 cm LF . They are multiple spawners and oocytes develop asynchronously. The proportion of mature (0·63) and reproductively active (0·70) females with ovaries containing postovulatory follicles indicated that they spawn almost daily. Batch fecundity for 15 females with the most advanced oocytes (>730 µm) ranged from 0·84 to 8·56 million eggs (mean ± s.d. = 3·06 ± 2·09). The relationships between batch fecundity (FB , in millions of eggs) and LF (cm) and round mass (MR , kg) were FB=9·91×10-14LF6·38 (r(2)  = 0·84) and FB=8·89×10-4MR2·05 (r(2)  = 0·80), respectively. The parameters estimated in this study are key information for stock assessments of T. obesus in the western Pacific Ocean and will contribute to the conservation and sustainable yield of this species.

Investigation of an electrochemically switched heterocyclization reaction on gold surface

We report an investigation of an electrochemically switched heterocyclization reaction on hydroquinone-terminated self-assembled monolayers (SAMs). This reaction involves an electrochemically modulated hydroquinone/benzoquinone transformation step in the SAMs and a subsequent heterocyclization step taking place between the electrochemically generated benzoquinone moieties in SAMs and l-cysteine in solution. The reaction process was monitored by XPS and electrochemical surface-enhanced Raman spectroscopy (EC-SERS). The surface reaction proceeds as a two-step reaction to give a benzothiazine product, which is in contrast to the much more complicated multiple step reactions in solution. This result suggests that the tight molecular packing in the SAMs does not hinder the intramolecular heterocylization reaction, but prevents the intermolecular coupling reaction from happening. This work provides insights to the control and detection of biomolecule related multistep reactions occurring at solid-liquid interface.

Separation, culture and identification of SD rat corpus cavernosal endothelial cells

The aim of the study is to investigate the methods of separation, culture and identification of Sprague Dawley (SD) rat corpus cavernosal vascular endothelial cells (CCECs). Cavernosal tissues were isolated from male SD rats. Enzymatic digestion was applied to separate CCECs. Purified cells were obtained using immunomagnetic beads and flow cytometric cell sorting and subcultured in EMG-2 medium. The growth curve of CCECs was measured by the tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. The cells were identified by von Willebrand factor (vWF) using immunofluorescence, and the positive percentage of vWF expression was detected by flow cytometry. The monomorphic cobblestone-like cells were observed by microscopy. High purification was obtained using immunomagnetic beads. After 2 days of incubation, cells entered the logarithmic growth phase and reached a plateau on the fifth day. The vWF expression in cytoplasm was positive. The purity of cells was 95.8%, which was tested by flow cytometry. SD rat CCECs can be separated and cultured successfully by the method of enzymatic digestion, immunomagnetic beads and flow cytometric cell sorting.

2-(Naphthalen-2-yl)azulene

In the title compound, C(20)H(14), a naphthalene ring system is linked at the 2-position to the 2-C atom of the five-membered ring of an azulene unit. The compound crystallizes with two reasonably similar mol-ecules in the asymmetric unit. Neither mol-ecule is perfectly planar: the r.m.s. deviations from the best fit planes through all non-H atoms are 0.092 and 0.091 Å for the two mol-ecules. The dihedral angle between the mol-ecular planes is 49.60 (4)°. The naphthalene and azulene ring systems are inclined at dihedral angles of 6.54 (12) and 5.68 (12)° in the two mol-ecules. The crystal structure exhibits two sets of parallel layers, a typical edge-to-face herringbone packing arrangement. The structure is stabilized by an extensive series of weak C-H⋯π inter-actions.

Piezoelectric dispenser based on a piezoelectric-metal-cavity actuator

A piezoelectric dispenser has been fabricated based on the idea of a piezoelectric-metal-cavity (PMC) actuator. The PMC actuator consists of a metal ring sandwiched between two identical piezoelectric unimorphs. The radial contraction of the piezoelectric ceramic is converted into a flextensional motion of the unimorph, causing a large flexural displacement in the center part of the actuator. With the PMC actuator as a fluid chamber, the large flexural actuation can be used to produce the displacement needed to eject fluid. By applying an appropriate voltage to the piezoelectric unimorphs, a drop-on-demand ejection of ink or water can be achieved. The efficiency of fluid ejection can be enhanced after installing a valve in the fluid chamber. With the simple PMC structure, the dispenser can be operated with a low driving voltage of 12-15 V.

[Etiological study on sporadic viral gastroenteritis among adult in Beijing]

OBJECTIVE

To understand the infection and epidemiology of norovirus and rotavirus and enteral adenovirus among adult with sporadic viral gastroenteritis in Beijing and provide theoretical basis for clinical prevention and control.

METHODS

Stool specimens were collected from all 312 sporadic outpatient among adult with non-cholera watery diarrhea in Infectious Disease Department of Peking University People's Hospital 2005-2006. PAGE were used for detection of rotavirus RNA in stool specimens; R-Biopharm RIDASCREEN norovirus and RIDASCREEN adenovirus were used for detection of norovirus and adenovirus.

RESULTS

Rotavirus RNA was not present in all 312 stool specimens; Norovirus was present in 17.6% (22/125) and in 32.4% (11/34) in October; Adenovirus was present in 3.3% (3/92); Mixed infections of norovirus and adenovirus was present in 1 stool specimen.

CONCLUSIONS

Norovirus is more common etiologic agents of sporadic acute viral gastroenteritis among adult in Beijing, The infection peak of norovirus is in autumn. Maybe the infection of rotavirus is few.

Catalytic wet air oxidation of coke-plant wastewater on ruthenium-based eggshell catalysts in a bubbling bed reactor

Catalytic wet air of coke-plant wastewater was studied in a bubbling bed reactor. Two types of supported Ru-based catalysts, eggshell and uniform catalysts, were employed. Compared with the results in the wet air oxidation of coke-plant wastewater, supported Ru uniform catalysts showed high activity for chemical oxygen demand (COD) and ammonia/ammonium compounds (NH3-N) removal at temperature of 250 degrees C and pressure of 4.8 MPa, and it has been demonstrated that the catalytic activity of uniform catalyst depended strongly on the distribution of active sites of Ru on catalyst. Compared to the corresponding uniform catalysts with the same Ru loading (0.25 wt.% and 0.1 wt.%, respectively), the eggshell catalysts showed higher activities for CODcr removal and much higher activities for NH3-N degradation. The high activity of eggshell catalyst for treatment of coke-plant wastewater can be attributed to the higher density of active Ru sites in the shell layer than that of the corresponding uniform catalyst with the same Ru loading. It has been also evidenced that the active Ru sites in the internal core of uniform catalyst have very little or no contribution to CODcr and NH3-N removal in the total oxidation of coke-plant wastewater.

Lead-free multilayer piezoelectric transformer

In this article, a multilayer piezoelectric transformer based on lead-free Mn-doped 0.94(Bi(12)Na(12))TiO(3)-0.06BaTiO(3) ceramics is presented. This piezoelectric transformer, with a multilayered construction in the thickness direction, is 8.3 mm long, 8.3 mm wide, and 2.3 mm thick. It operates in the second thickness extensional vibration mode. For a temperature rise of 20 degrees C, the transformer has an output power of >0.3 W. With a matching load resistance of 10 Omega, its maximum efficiency approaches 81.5%, and the maximum voltage gain is 0.14. It has potential to be used in low voltage power supply units such as low power adapter and other electronic circuits.

4-1BB promotes long-term survival in skin allografts treated with anti-CD45RB and anti-CD40L monoclonal antibodies

4-1BB (CD137) is a T-cell co-stimulatory molecule that promotes T cell activation. Using a skin transplantation model, we observed that simultaneous administration of monoclonal antibodies (mAb) targeting CD45RB and CD40L prolonged skin allograft in co-stimulation blockade (CTLA4-Ig and anti-CD40L mAb)-resistant mice, because of reducing CD8(+) T cells and CD4(+) CD45RB(high) T cells. Anti-CD45RB mAb (45RB) blocks the activation of T helper 1 (Th1) cells and generates regulatory T cells (T(reg)). The experimental design included five groups: group 1, control; group 2, 45RB-MR1; group 3, 45B-MR1 + 4-IBBL; group 4, anti-CD4 mAb plus group 3 treatment; group 5, anti-CD8 mAb plus group 3 treatment. In this study we highlight the involvement of 4-1BB/4-1BBL in the development of T-cell responses. C57BL/6 recipients of BALB/c skin grafts were treated with 45RB, anti-CD40L mAb (MR1), and antagonistic anti-4-1BBL mAb (4-1BBL) on days 0, 2, 4, 6, and 8 posttransplantation. Additional 4-1BBL further prolonged skin graft survival, although the percentage of splenocyte-derived CD8(+) T cells was reduced similarly in both groups. Use of 4-1BBL seems to have additive effects on T(reg) cells, which play a major role in the maintenance of tolerance. Even after immunosuppressive therapy in combination with CD4(+) T-cell depletion, we did not achieve prolonged graft survival, possibly because of the absense of T(reg) cells, which require CD4-independent CD8(+) T cells, based on the observation of increasing proportion of CD8(+) T cells in similar degree as the control group.

Apaf-1 overexpression partially overcomes apoptotic resistance in a cisplatin-selected HeLa cell line

Inhibition of caspase-3-mediated apoptosis has been hypothesized to be associated with chemoresistance. Investigations of apoptosis revealed that cytosolic cytochrome c is associated with a complex of apoptotic protease activating factor-1 (Apaf-1), an adapter molecule, and caspase-9 to activate caspase-3. However, whether these apoptotic molecules are involved in acquired cisplatin resistance is not understood. The present work shows reduced activation of caspase-3 and apoptosis in a cisplatin-selected HeLa cell line. Ac-DEVD-CHO, a caspase-3 inhibitor, inhibited cisplatin-induced apoptosis about 60-70% in both cell lines. Ac-LEHD-CHO, a caspase-9 inhibitor or Ac-IETD-CHO, a caspase-8 inhibitor, inhibited cisplatin-induced caspase-3 activation and apoptosis similarly in both cell lines. In addition, cisplatin induced the activation of caspase-9, the upstream activator of caspase-3, in a dose-dependent manner, and the activation of caspase-9 was less induced in resistant cells. The accumulation of cytosolic cytochrome c, an activator of caspase-9, and the induction of the mitochondrial membrane-associated voltage-dependent anion channel were also reduced in cisplatin-resistant cells. However, the concentration of Bcl-2 family proteins in cisplatin-resistant cells was normal. The concentration of Apaf-1 was unaltered in both cell lines. Increasing the cellular concentration of Apaf-1 through the transient expression of the gene increased the induction of apoptosis in resistant cells, associated with enhanced activation of caspase-9, caspase-3 and DNA fragmentation factor. Regression analysis reveals that the modification factor, the ratio of the slope in the linear range of the dose-response curve with Apaf-1 to the slope without Apaf-1, is 1.5 and 4.75 in the HeLa and cisplatin-resistant HeLa cells, respectively. These results indicate that apoptosis and caspases are less induced in cisplatin-selected HeLa cells. They also suggest that ectopic overexpression of Apaf-1 may partially reverse the acquired cisplatin resistance.

Fluorescent in situ hybridization detection of HER-2/neu gene amplification in rhabdomyosarcoma

Embryonal rhabdomyosarcoma is the most common malignant soft-tissue tumor in childhood, comprising 45-50% of childhood sarcomas. Cytogenetic studies of this tumor are rare. In view of the paucity of cytogenetic data on this cancer and based on the finding of HER-2/neu gene amplification in a number of cancers that was detected mostly using the traditional technique of immunohistochemistry, we decided to conduct a pilot study to investigate whether HER-2/neu gene amplification in this tumor can be detected using the newer technique of fluorescent in situ hybridization (FISH). Archival tissues of rhabdomyosarcoma were retrieved and FISH using an HER-2/neu probe was undertaken on formalin-fixed paraffin-embedded tissue sections using a protocol optimized for our laboratory at Rhode Island Hospital. Out of 9 cases of rhabdomyosarcoma studied to date, 1 case clearly showed HER-2/neu gene amplification. Thus, FISH is a sensitive technique suitable for the detection of oncogene amplification and the delineation of tumor heterogeneity in this tumor. Future experiments utilizing additional specimens from our centers as well as from other laboratories will be needed to extend the finding in the present pilot study.

Assessment of chromosomal trisomies in prostate cancer using fluorescent in situ hybridization

In a previous study, we observed a low frequency of HER-2/neu oncogene amplification in prostate cancer using fluorescent in situ hybridization (FISH). In our continued effort to identify prognostic biomarkers in prostate cancer, we analyzed 74 cases of prostate cancer to assess the presence of chromosomal trisomies in this cohort of patients. Previous results from this laboratory have implicated a role of chromosomal trisomies in various cancers. FISH using a chromosome 7 and a chromosome 8 centromere probe was utilized to study abnormal chromosome copy numbers together with data from a chromosome 17 control. The frequency of trisomy 7 was found to be 58.1% (43 of 74 informative cases), while the frequency of trisomy 8 was found to be 9.5% (7 of 74 informative cases). The frequency of cells showing chromosome 17 trisomy was 18.5% (15 of 81 cases successfully studied). While chromosome 8 trisomy did not seem to play as significant a role here as in other cancers that we studied, the results of chromosome 7 trisomy are consistent with those reported in the literature. Further exploration of selected trisomies as biomarkers in prostate cancer using a larger study sample size is warranted to establish their clinical utilities.

HER-2/neu oncogene amplification in cervical cancer studied by fluorescent in situ hybridization

Oncogene amplification, such as HER-2/neu (C-erbB-2), is a manifestation of genetic instability often associated with the genesis and progression of cancer, including cervical cancer. Oncogene overexpression is traditionally studied using immunohistochemistry. We previously reported studies of oncogene amplification in breast cancer using fluorescent in situ hybridization (FISH), where the data support the hypothesis that HER-2/neu is a prognostic marker of poor outcome. To explore further the possible significance of HER-2/neu oncogene amplification in cervical cancer, we conducted a pilot study of 24 cervical cancer cases. The HER-2/neu FISH probe (Vysis, Inc., Downers Grove, IL) was used to measure gene amplification, with a chromosome 17 centromeric probe as an internal control. Out of 24 cases studied, 23 were informative. Of the 23 informative cases, 2 (8.7%) were found to be amplified. The rest (21 out of 23 or 91.3%) were nonamplified. Both amplified cases were invasive adenocarcinoma. Although the sample size of this pilot study may be somewhat small, the data obtained so far clearly demonstrated that detection of oncogene amplification in cervical cancer is not only feasible but is very sensitive, and suggest that further exploration using a larger sample size may be warranted.

Fluorescence in situ hybridization study of HER-2/neu oncogene amplification in prostate cancer

Prostate cancer is a serious disease affecting men worldwide and treatment compromises the quality of life of prostate cancer patients. We conducted a study of 88 cases of prostate cancer in an attempt to identify prognostic biomarkers that can distinguish aggressive cases that must be treated immediately. HER-2/neu oncogene amplification was initially studied because amplification of this gene has been reported in many other cancers, including those studied in this laboratory. Fluorescence in situ hybridization (FISH) using a HER-2/neu gene probe with a chromosome 17 centromere control probe was performed on formalin-fixed, paraffin-embedded tissues. Of a total of 86 cases successfully analyzed, only 8 (9.3%) were found to be amplified. This frequency was lower than the frequency of amplification found in other cancers studied. Furthermore, no case was found where the level of amplification can be considered high. Only one case was found to have moderate amplification. The rest of the positive cases can all be classified as low amplification. Thus, while we have demonstrated that FISH is a sensitive technique for detecting oncogene amplification, the frequency and level of HER-2/neu amplification detected in prostate cancer seem to be lower than those in most cancers that we studied. In view of the fact that HER-2/neu amplification does not seem to play as significant a role, exploration of other biomarkers in prostate cancer is warranted.

HER-2/neu gene amplification in stages I-IV breast cancer detected by fluorescent in situ hybridization

PURPOSE

Approximately 25-30% of breast and ovarian carcinomas have amplification of the HER-2/neu oncogene. The aim of the present study was to focus on HER-2/neu gene amplification in different clinical stages of breast cancer in order to (1) determine if fluorescent in situ hybridization (FISH) can be used to detect HER-2/neu gene amplification in different clinical stages of breast cancer, (2) establish whether HER-2/neu gene amplification characterizes a subset of breast cancer in each of these stages, and (3) determine whether a trend for correlation of amplification with the clinical stage of the disease can be detected using the FISH technology.

METHODS

A total of 40 specimens of formalin-fixed, paraffin-embedded breast cancer tissues were analyzed cytogenetically, in a blinded fashion, for HER-2/neu gene amplification using FISH and the Vysis LSI HER-2/neu Orange and CEP 17 Green DNA dual color probe. The criterion for "high amplification" was an amplification ratio of >4.0, that for "moderate amplification" a ratio between 2.1 and 4.0, and that for "low amplification" a ratio of 1.5-2.0.

RESULTS

Using a cutoff point of > or =1.5, the overall frequency of HER-2/neu gene amplification among stage I tumors was 30% (3 out of 10). Of these, one-third (1 out of 3) showed low amplification, one-third (1 out of 3) were moderately amplified, and one-third (1 out of 3) were highly amplified. The overall frequency of HER-2/neu gene amplification among stage II tumors was 0% (0 out of 10). The overall frequency of HER-2/neu gene amplification among stage III tumors was 10% (1 out of 10). The sole tumor found positive was classified as moderately amplified by our criteria. The overall frequency of HER-2/neu gene amplification among stage IV tumors was 50% (5 out of 10). Four of the 5 tumors found positive were highly amplified. The overall frequency of gene amplification in the 40 cases studied was 22.5% (9 out of 40 tumors studied).

CONCLUSION

Although a linear correlation between HER-2/neu amplification and clinical stage cannot be established at this time, it is interesting to note that when stages I and II, and when stages III and IV are combined, respectively, the latter category has a higher amplification frequency than the former. Furthermore, stage IV has the highest frequency (5 out of 10) of HER-2/neu gene amplification than all three lower stages combined (4 out of 30). This is no doubt due to the high frequency of gene amplification observed in stage IV tumors, which, interestingly, also demonstrate high level amplification of HER-2/neu gene copy numbers. Although the biologic and clinical basis for gene amplification is not clear, given the observation that the most aggressive disease stage is associated with the highest frequency of gene amplification and the most high level amplification, further exploration of HER-2/neu as a prognostic marker of poor outcome using FISH is warranted.

Study of chromosome 12 copy number in breast cancer using fluorescence in situ hybridization

Trisomy 12 is the most frequent numerical chromosomal abnormality reported in chronic lymphocytic leukemia (CLL). Its significance in other cancers, however, has not been extensively investigated until recently. Less than 20 cases of polysomy for chromosome 12 have been studied thus far. The most recent data in the literature suggest that gain of chromosome 12 may be a recurrent and sometimes early event in breast carcinogenesis. To test the hypothesis that a subset of breast cancer may be characterized by chromosome 12 trisomy, we conducted a retrospective study of 40 specimens. Of these, ten were stage I, ten were stage II, ten were stage III, and ten were stage IV. Out of the total sample, 12 cases (30%) were found to be presumably trisomic, if a conservative cutoff point of greater than or equal to 15% cells with three signals is adopted. Furthermore, some, but not all, of the 12 cases were found to be likely triploid, when data from a control chromosome 17 probe were taken into account. Thus, our data support the hypothesis that a subset of breast cancer exists which is characterized by an abnormal copy of chromosome 12, in either a diploid or a triploid background.

Abnormal chromosome 8 copy number in stage I to stage IV breast cancer studied by fluorescence in situ hybridization

To test the hypothesis that the frequency of abnormal chromosome 8 copy number increases with the severity of the disease as defined by an increase in clinical stage, we conducted a fluorescence in situ hybridization (FISH) study of a sample of 42 breast cancer specimens utilizing a protocol that was optimized by our laboratory. Cytogenetic results, obtained from blinded analyses of archival specimens, demonstrated that the higher clinical stages (i.e., stages III and IV) yield higher frequencies of abnormal chromosome 8 copy number. Specifically, 45.45% and 50% of the stage I and stage II cases, respectively, were abnormal, whereas 63.64% and 60% of the stage III and stage IV cases, respectively, were abnormal for chromosome 8 copy number. The overall frequency of abnormal chromosome 8 copy number was 54.76% (23 of 42 tumors studied). When the results of a control probe were taken into account, 34.78% (8 of 23) of the abnormal cases were trisomic, whereas the remaining cases were likely triploid. Thus, the present data not only established that chromosome 8 trisomy is a recurrent finding in breast cancer, but also confirmed a higher frequency of occurrence of abnormal chromosome 8 copy number with the higher clinical stages. Future experiments utilizing additional specimens in this laboratory and from other laboratories are necessary to confirm and extend the findings of the present study.

[Effect of intrahippocampal microinjection of enkephalin on cellular immune function and brain IL-1 alpha gene expression in rat]

The effect of intrahippocampal microinjection of enkephalin on cellular immune function and hippocampal IL-1 alpha gene expression was studied in rats. The results showed that: (1) The proliferation activity of splenic lymphocytes stimulated by Con A was significantly increased with microinjection of Leu-enkephalin 1 microliter (18 mmol/L) or Met-enkephalin 1 microliter (18 mmol/L) into bilateral hippocampus, but was inhibited by Lipopolysaccharide 1 microliter (50 ng/microliter). The proliferative response of splenic lymphocytes to Leu-enkephalin still persisted after bilateral adrenalectomy. Low doses of Leu- or Met-enkephalin (10(-10), 10(-11) mol/L) were also capable of causing proliferative activity of the Con A- stimulated cultured splenic lymphocytes in vitro. (2) Using RT-PCR technique, IL-1 alpha gene expression was detected in hippocampus 90 min after bilateral intrahippocampal injection of LPS. The LPS-induced IL-1 alpha gene expression in hippocampus could no longer be detected 30 min after microinjection of Met- or Leu-enkephalin into hippocampus. The above results suggested that intrahippocampal enkephalin might play an important role in neuro-immunomodulation by enhancing the inhibition of IL-1 alpha gene expression in hippocampal formation.

[Improvement of memory function of fornix-fimbria transected rats by transplantation of the superior cervical ganglion into hippocampus]

Memory impairments of passive avoidance response were observed in 38 Wistar rats with bilateral fornix-fimbria transection. After fornix-fimbria lesions the degree of performance decreased from 65.3% to 13.6% (P < 0.01). Autotransplantation of superior cervical ganglion (SCG) into bilateral dorsal hippocampi improved memory function to a considerable extent. In the end of the behavioral experiments, implanted rats were sacrificed for histofluorescence study of grafts and measurement of norepinephrine (NA) content in the hippocampus. These experiments showed that the hippocampal NA content in implanted rats was considerably higher than that in untransplanted fornix-fimbria transected rats and consequently suggested that improvement of memory function was to some extent due to supplement of monoamine transmitter by the transplanted SCG.

Opiate mixed agonist-antagonist interactions with histamine antagonists vs. morphine

Anecdotal reports of polydrug abuse in humans using tripelennamine and pentazocine prompted our investigation of drug interactions between tripelennamine, morphine and various synthetic mixed agonist-antagonists in mice. Pentazocine, nalbuphene and butorphanol, at doses of 4.0-8.0 mg/kg, all showed frank or borderline intrinsic antinociceptive activity and potentiated the tripelennamine response, whereas cyclazocine, an experimental compound with very strong mixed agonist-antagonist qualities at 5.0 mg/kg, showed intrinsic antinociceptive activity but was not potentiated by tripelennamine and actually blocked the tripelennamine response. In a comparative study, pentazocine, butorphanol and nalbuphene had no effect on morphine antinociception whereas cyclazocine completely abolished the antinociceptive effects of morphine. Cimetidine blocked the response of cyclazocine, but not nalbuphene, pentazocine or butorphanol. Our findings demonstrate that the mechanism of action of cyclazocine is significantly different from that of the other mixed agonist-antagonists studied. They also suggest possible histaminergic involvement in antinociception, as well as a locus for antinociception separate from the opiate receptor.